Perversely, for a few seconds, it seemed as if the flames would die. They burned low, threatening to flicker away, and then he saw the first strands of rope catch, curl and flare into yellow flame. Then the shavings caught. Suddenly there was a spread of flame and Toby backed away.

The moment had not quite come. He did not know how long it would take the fire to catch, but he could not wait here in fear. He lit two more strakes, putting one in a pile of shavings beneath a half-completed boat, the other beneath the rack of curved strakes, and then, afraid of being seen in the growing illumination, he went back to the shadows by the wharf.

The flames were lurid in the boat shed, licking up the boat on its trestles. Surely someone would see! He waited, apprehensive, knowing the enormity of his act. The first fire, in the timber stack, seemed dim. He wondered if it had gone out.

Deep in the great timber stack was a draft, coming in at the base, then funnelling up to stack’s top at the roof of the shed. Unseen to Toby, the flames were being sucked into the natural chimney caused by the stack’s construction. He was biting his lip, wondering whether he should recross the yard and feed the dim fire, when suddenly there was an explosion of flame, sparks and smoke. The stack had caught.

It caught spectacularly, the fire spreading through the interior by the chimney. One moment Toby could see a dull glow at the base, the next the whole roof of the shed was burning, there was a roar of flame, and Scammell’s yard was lit like daylight. Sparks whirled crazily upward, flames illuminating the base of the plume of smoke that rose above the city. Already there were shouts from the street: “Fire!”

The blaze was roaring, feeding itself, spreading across the shed’s roof and dropping burning fragments into the yard. Toby looked to his right and saw Scammell’s face, appalled, at the window. He gripped the handle of his sword. The moment was coming!

Fists battered on the yard gate, voices shouted. The noise was huge now with the sound of flames and of panic, and Toby looked left to see the boat-shed tangled in fire. Scammell’s business was gone, destroyed.

The watch raised the alarm. The church bell started tolling. All across the city people would look from their windows wondering if the fire would spread. Whole towns had been destroyed by fires that started as tiny, insignificant flames.

Timbers crashed in the stack, spreading the blaze to adjoining stacks, and then more light, feeble by comparison, was thrown into the yard. Scammell stood in his candle-lit doorway, his mouth slack, eyes staring at the churning red-gray smoke that billowed over his yard. He ran to the gates, shouting incomprehensibly and began to lift the bar to let the watch in. The heat was fearsome.

Toby was watching the window. He could see the big man, his round, broken-nosed face frightening, staring at the flames. He still held Campion, one hand in her hair, forcing her head down. He turned and said something to the others in the room.